10 2.5" drums are they all the same?

I've never had a problem swapping them around. I keep them matched in pairs, as in, don't put a finned one on one side and a smooth one the other. I like to keep them matched fairly close on the measurement too for the same reason. They can heat and cool differently and cause a pull to one side. Not much of problem on the rear, but, it can be more pronounced in the front. The finned ones tend to be heavier than the smooth ones. They make both steel and cast iron versions too along with different manufacturers, so, I would imagine weights will be all over the scale.